PREP1题，不懂

chenliqiang

Q3.  p2-cr       1.    (24021-!-item-!-188;#058&000691)

 

On Pacific islands, a newly arrived gecko species, the house gecko, is displacing the previously established mourning gecko in urban areas, but populations of the two species are more stable in rural areas far from human settlement.  The house gecko does not attack the mourning gecko, but in areas where insects congregate it prevents the mourning gecko from feeding on them.

 

Which of the following contributes most to an explanation of the difference between gecko populations in urban and rural areas?

 

(A) In urban areas, geckos are valued because they eat so many insects.

(B) Geckos defend territories against other members of the same species.

(C) House geckos that arrive on islands are carried there in boats and planes.

(D) In places where there are lighted buildings, insects tend to gather around the light.

(E) Mourning geckos are all females and reproduce asexually, but house geckos reproduce sexually.

答案居然是D。。。。为什么啊，牛牛请教

tamama

在市區兩種gecko數目不平衡, 但是在郊區數目是穩定的. mourning gecko的食物是insect,house gecko在insect聚集的地方阻止了mourning以insect為食

很明顯mourning少了食物數量就會下降, 再加上題目排除了一種可能性就是house會攻擊mourning而導致mourning數量下降. 如果insect聚集的地方就是市區, 那麼mourning的數量應該是下降.

D中lighted building接近於urban areas, not rural areas far from human settlement, gather around=congregate

cnrnld

今天也做到这题，想了一会儿才觉得是D。

题干是说城郊两处的两类geckos数量对比不同：郊区远离人居处两者数量均衡稳定，市镇中则house gecko逐渐占据主流。题中又称house g并不攻击mourning g，但在昆虫聚集处前者会阻止后者进食昆虫。

问原因是什么？其实就是要在城郊两处的数量对比不同与昆虫之间建立联系，因为昆虫/进食是两者数量对比不同的原因（其中一类是饿死的）。只有D提及到市镇中昆虫会为建筑物灯光吸引聚集起来。

agan14404102

有道理 唉 晕死了逻辑